This invention relates in general to methods of making inductive devices having improved termination arrangements. The invention is more particularly and concisely described in connection with dynamoelectric machines, e.g., electric motors.
Terminal connections to dynamoelectric machines of the type of particular interest herein may take many diverse forms. Some terminal connectors are of the solder type requiring the stripping of insulation from a wire and then the soldering of the wire to the terminal connector itself. This is a costly and time-comsuming operation when performed in a production line, and produces an inflexible circuit connecting arrangement for use in the field. In one prior arrangement a terminal is provided that will accept insulated wires and then the terminal and wires are welded thus melting the insulation on the wires. In these prior arrangements, the terminals must be protected by insulating them and providing strain relief for the lead wire.
There is a definite advantage of forming terminal receptacles in a molded insulating body formed for inductive devices whether these inductive devices are for transformer cores, relays, generators or electric motors. The molded insulation provides a protective covering for the terminal thereby protecting it from physical contact with other conductive elements. Where the insulation is molded in situ, an additional economic saving is realized since the additional cost for providing a terminal receptacle as part of the molding is minuscule. Once the molding apparatus is modified to produce the proper molded insulation form and terminal arrangement, all subsequent molded parts are produced without any additional effort.
In many prior approaches the arrangement of parts of a given device using a particular connection scheme is dictated by the connecting or termination approach that is to be followed by an end user of such device, and once such arrangement has been made the device is not readily adaptable to other types of connecting techniques. For example, when one of these approaches is selected, capital expenditures usually are made and product design is relatively frozen visa-vis the connections. Moreover, each of the approaches just mentioned have deficiencies. For example, in operations requiring soldering or welding, precautions must be taken to avoid overheating and thus damaging a winding of an inductive device whether such device is a relay coil or winding turns of an electric motor, generator (or alternator), or transformer. In addition, stress relief must be provided for the lead wires so as to avoid breakage or damage during handling, assembling, testing, and final use.
Solutions of the above problems will be discussed in more detail hereinafter with particular reference to electric motors and it will be appreciated that these problems will also be encountered in the manufacture of other inductive devices including those just mentioned. Thus, it will be seen that the resolution of these and other problems would be particularly desirable.
Accordingly, it is an object of the present invention to provide an improved method of making an inductive device having a termination arrangement for holding lead connections in a body of insulation.
Another object of the invention is to provide a method of assembling an improved inductive device having a termination arrangement for holding lead connections in a body of insulation.